Question about derma and NPC's

[Chimpanzee]

I was wondering recently how to make a simple NPC that sells you armor, or health or anything of the sort. For example, just a regular NPC.

Walk up to it and press E, a small menu would open with a button that says "Buy Armor ($50)" {or something like that} and also an x button to close out.

I've been looking around and quite frankly I'm not the greatest with derma.

The commands to buy health/armor are already taken care of, just need the NPC to be taken care of. If I could get some pointers in a direction to show me where I should go, it would help a lot.
(And no, by this I don't mean link me to a wiki page)

Any help is greatly appreciated!

[rejax]

on ENT:Use, send a net message to the player to open a menu

when the player clicks the buy button, send a message to the server (which will then verify that the player has the money) and then give them armor

[Acecool]

An alternative is using AcceptInput:
[lua]function ENT:AcceptInput( Name, Activator, Caller )
// If the input is the Use key, and a player did it
if Name == "Use" and Caller:IsPlayer( ) then
// networking -- networking:SendToClient( "ShopNPCUsed", Caller, self.shopid );

end
end[/lua]

[Chimpanzee]

This might be a lot to ask but if anyone is up for it could you please supply me with an example code for the derma linking to a use function with the specified code in mind. Most tutorials that I've seen completely pass by what I want and I have to guess functions, etc so I can't do much. I didn't come here to just ask someone to make me a code but if it's possible to give me a code like such for future reference I would very much appreciate it

[Acecool]

With the example above, in the place of //networking you'd do something like

[lua]net.Start( "NameOfMessage" ); net.Send( Caller );[/lua]

Also, in a server file make sure you call:

[lua]util.AddNetworkString( "NameOfMessage" );[/lua]

then on the client:

[lua]net.Receive( "NameOfMessage", function( len )
local _panel = vgui.Create( "DPanel" );
_panel:SetSize( 500, 500 );
_panel:Center( );
end );[/lua]